Slot antenna with orthogonally positioned slot segments for receiving electromagnetic waves having different polarizations

ABSTRACT

An antenna for receiving electromagnetic waves having different polarizations that comprises a plurality of slots defined by a piece of metal, and each of the plurality of slots includes at least two continuous segments. In addition, for each of the plurality of slots: a first segment of the at least two continuous segments is: (i) defined by the piece of metal in a first dimension, and (ii) configured to receive radio frequency (RF) power transmission waves having a first polarization, and a second segment of the at least two continuous segments is: (i) defined by the piece of metal in a second dimension, distinct from the first dimension, and (ii) configured to receive RF power transmission waves having a second polarization different from the first polarization.

This application is a continuation of U.S. patent application Ser. No.14/930,531, filed on Nov. 2, 2015, entitled “3D Triple Linear AntennaThat Acts As Heat Sink,” which is herein fully incorporated by referencein its respective entirety.

TECHNICAL FIELD Background

Wireless charging of batteries of electronic devices has historicallybeen performed by using inductive coupling. A charging base stationreceiver of an electronic device may have one or more coils in which acurrent may be applied to produce a magnetic field such that whenanother coil is place in close proximity, a transformer effect iscreated and power is transferred between the coils. However, suchinductive coupling has a short range limit, such as a few inches orless. Examples of such wireless charging include electronic toothbrushesthat are placed on a charging stand and inductive pads inclusive of oneor more coils to enable electronic devices with coil(s) to be placed onthe pads to be charged.

While inductive charging is helpful to eliminate users having to plugpower cords into electronic devices for charging, the limited range atwhich electronic devices have to be positioned from charging stations isa significant shortcoming of the inductive charging technology. Forexample, if a user of a mobile device, such as a mobile telephone, is ina conference room without a charging pad or sufficient number ofcharging pads, then the user is unable to charge his or her phonewithout a traditional power cord.

Remote wireless charging has recently been developed. Remote wirelesscharging operates by generating a wireless signal inclusive ofsufficient power to charge a battery of an electronic device. Suchtechnology, however, has been limited due to technology advancementsbeing a challenge, as transmitters, receivers, antennas, communicationsprotocols, and intelligence of transmitters have all had to be developed(i) so that sufficient wireless power is able to be wirelessly directedto charge electronic devices and (ii) so that the remote wirelesscharging is effective and safe for people.

Electronic devices are becoming smaller and as such, receivers andantennas for receiving wireless power to charge the electronic devicesare also to become smaller. Such receivers and antennas are to be ableto receive multi-polarized wireless power signals in order to be moreefficient in receiving and charging wireless power signals.

SUMMARY

An antenna adapted to be used by a remote wireless charging receiver atan electronic device may include a printed circuit board on which anapplication specific integrated circuit (ASIC) may be attached to and/orsupported by a stamped 3D slot dipole antenna that also operates as aheat sink. The use of the stamped slot dipole antenna actually providesfor multiple antenna elements, such as four, that may receive signals inthree orthogonal planes. As a result, the receiver may operate in anefficient manner when receiving a wireless power signal that isdual-polarized or circularly polarized, and allows the receiving antennato be in any orientation relative to the transmitter antenna withoutlosing efficiency.

One embodiment of a receiver for receiving wireless waves to power adevice may include an electronic circuit configured to receive wirelessradio frequency waves and convert the radio frequency waves into asignal that can be used to power the device. An antenna device may beconfigured to at least partially house the electronic circuit and tooperate as a heat sink for the electronic circuit. The antenna mayfurther be configured to receive the radio frequency waves in aplurality of polarizations (e.g., x, y, and z-axes). In housing theelectronic circuit, the antenna may cover the electronic circuitpositioned on a PCB. There may be three polarizations.

One embodiment of a method of manufacturing a receiver antenna and heatshield may include providing a piece of metal. The piece of metal may bestamped to form a 3D slot dipole antenna. The 3D slot dipole antenna maybe secured to a printed circuit board inclusive of an electronic circuitto form a receiver configured to receive and convert wireless power.

One embodiment of an antenna may include a piece of metal definingmultiple antenna sections inclusive of 3D slot dipoles. The 3D slotdipoles may be configured to receive RF signals in multiplepolarizations.

Additional features and advantages of an embodiment will be set forth inthe description which follows, and in part will be apparent from thedescription. The objectives and other advantages of the invention willbe realized and attained by the structure particularly pointed out inthe exemplary embodiments in the written description and claims hereofas well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings constitute a part of this specification andillustrate an embodiment of the invention and together with thespecification, explain the invention.

FIG. 1 is an illustration of an illustrative wireless power environmentin which transmitters may be configured to identify locations of one ormore receivers inclusive of stamped 3D slot dipole antennas, and tocommunicate wireless power signals to those receiver(s) to form energypocket(s) thereat, according to an exemplary embodiment;

FIG. 2 is an illustration of an illustrative PCB for mounting an ASICconfigured to convert RF signals communicated as remote wireless powersignals, according to an exemplary embodiment;

FIG. 3 is an illustration of an illustrative stamped 3D slot dipoleantenna, according to an exemplary embodiment;

FIG. 4 is an illustration of an alternative illustrative stamped 3D slotdipole antenna, according to an exemplary embodiment;

FIG. 5 is an illustration of the stamped 3D slot dipole antenna of FIG.3 mounted to the PCB of FIG. 2, according to an exemplary embodiment;

FIGS. 6A and 6B are illustrations of respective top and bottom isometricviews of an alternative illustrative stamped 3D slot dipole antenna,according to an exemplary embodiment; and

FIG. 7 is a flow diagram of an illustrative process for manufacturing areceiver inclusive of a 3D slot dipole antenna to receive wireless powersignals to charge a battery of an electronic device.

DETAILED DESCRIPTION

The present disclosure is herein described in detail with reference toembodiments illustrated in the drawings, which form a part here. Otherembodiments may be used and/or other changes may be made withoutdeparting from the spirit or scope of the present disclosure. Theillustrative embodiments described in the detailed description are notmeant to be limiting of the subject matter presented here. Alterationsand further modifications of the inventive features illustrated herein,and additional applications of the principles of the inventions asillustrated herein, which would occur to one skilled in the relevant artand having possession of this disclosure, are to be considered withinthe scope of the invention.

Referring to FIG. 1, an illustration of an illustrative wireless powerenvironment 100 in which transmitters 102 a, 102 b (collectively 102)are configured to identify a location of an electronic device 104 with areceiver 106 (or multiple receivers) inclusive of one or more receiverantennas (e.g., cross-polarized dipole antenna), and transmit wirelesspower signals or waves to the receiver 106 to cause RF signalconstructive interference to form at the receiver 106 is shown. Althoughdepicted with multiple transmitters 102, it should be understood that asingle transmitter may be utilized. The transmitters 102 a, 102 brespectively include antenna arrays 108 a, 108 b (collectively 108)inclusive of respective antenna elements 109 a-109 m, 109 n-109 z(collectively 109). The transmitters 102 are used to transmit wirelesspower signals 110 a, 110 a (collectively 110) via the antenna elements109. In one embodiment, the antenna arrays 108 a, 108 b have the samenumber of antenna elements. Alternatively, the antenna arrays 108 a, 108b have a different number of antenna elements. Still yet, the antennaarrays 108 a, 108 b may have the same or different layouts orconfigurations of antenna elements. The antenna arrays 108 a, 108 b mayhave regularly spaced antenna elements or subsets of antenna elementswith different spacings that are used for different types oftransmissions of the wireless power signal.

Because the transmitters 102 are meant to be positioned in householdsand commercial settings, such as conference rooms, the transmitters 102are to be sized in a manner with a small footprint and/or profile.Although the size of the footprint (e.g., width of overall antennaarrays) in some cases has to have a certain length for creating smallenergy pockets, the profiles (e.g., length of the antenna elements 109along the z-axis that define the distance that the transmitters 102extend from a wall) can be reduced to be more commercially viable foradoption by consumers and businesses.

The transmitters 102 may also include communication components 112 a,112 b (collectively 112) that communicate with the electronic device104. In one embodiment, the receiver 106 may be configured with atransmitter or other circuitry that enables communication with thecommunication components 112, thereby enabling the transmitters 102 tofocus the wireless power signals 110 at the receiver 106 to form anenergy pocket 114. The energy pocket 114 may be a localized region atwhich wireless power waves 110 form constructive interference (i.e.,peaks of oscillation signals coincide and add constructively) thatproduces a combination of peak signals from each of the wireless powersignals 110.

Because the antenna arrays 108 may have orientations that cause thewireless power signals 110 to be communicated at different polarizationsdepending on an orientation of the electronic device with respect to therespective antenna arrays 108, the receiver 106 may include across-polarized dipole antenna, for example, so that orientation of thereceiver 106 with respect to the antenna arrays 108 has minimal impactin an amount of power that is received from the wireless power signals110.

To provide for cost effective antenna arrays 108, a structure for eachof the antenna elements 109 may utilize a design that has a minimalnumber of parts and simplistic assembly process. The antenna element maybe configured to transmit a wireless power signal having a frequencyover 900 MHz to be transmitted to charge or operate a wireless device.In an embodiment, the antenna arrays 108 are configured to transmit atfrequencies over 1 GHz. However, the antenna arrays 108 can beconfigured to operate at frequencies in a range from over 1 GHz to 100GHz. More specifically, the center frequency may be about 1 GHz, 5.8GHz, 24 GHz, 60 GHz, and 72 GHz with bandwidths suitable for operation(e.g., 200 MHz-5 GHz bandwidths), and the dimensions may be configuredto accommodate the frequencies of operation. The wireless power signalmay be an RF signal that is circularly polarized or dual-polarizeddepending on the configuration of the antenna, as understood in the art.

With regard to FIG. 2, an illustration of an illustrative PCB 200 formounting an electronic device, such as an ASIC, configured to convert RFsignals communicated as remote wireless power signals is shown. The PCB200 includes a dielectric material 202 disposed on a substrate 204, asunderstood in the art. Conductive lines 206 a-206 d (collectively 206)are configured to receive and conduct RF signals from an antenna. A pad208 on which an electronic circuit, such as an ASIC, may be affixed iscentrally located on the PCB 200. It should be understood that the pad208 may be located elsewhere on the PCB 200. Conductive pads 210 thatmay extend through thru-hole vias 212 (i.e., conductors through the PCB200) may be utilized to conduct signals, such as power signals, from theelectronic device positioned on the pad 208 to another device, such as amobile telephone, for charging a rechargeable battery or otherwiseoperating the electronic device.

With regard to FIG. 3, an illustration of an illustrative stamped 3Dslot dipole antenna 300 is shown. The antenna 300 includes four antennaregions 302 a-302 d (collectively 302). Within each of these antennaregions 302, four 3D slot dipoles 304 a-304 d (collectively 304) arepositioned. Each of the 3D slot dipoles are shown to include dipoleslots 306 x, 306 y, and 306 z that are orthogonal to one another, suchthat the antenna regions 302 are each configured to receive RF signalsthat are dual polarized or circularly polarized in any of the axes,thereby being more efficient than if the slots were oriented in only oneor two planes. Having the dipole slot 306 z enables receiving RF signalswhen the antenna 300 is oriented orthogonal to the transmitter antennaif transmitting dual-polarized RF signals.

The antenna 300 also includes a plurality of feet 308 a-308 d(collectively 308) that may be attached to conductive lines 206 of FIG.2 to support the antenna 300 and to transfer RF signals received by the3D slot dipoles 304 to an electronic circuit residing on the PCB 200 forconverting wireless power signals into wireless power for use incharging or powering an electronic device. The antenna 300 may includechamfers 310 a-310 d (collectively 310) that may be used to enablebending of the antenna regions 302 to form a vertical height H so as toprovide for the z-axis dipole slot 306 z for each of the antenna regions302. The antenna 300 may be a stamped piece of metal, which provides forlow-cost manufacturing, as understood in the art. By using a single,stamped piece of metal for producing the antenna 300, manufacturing andassembly complexity may also be minimized.

With regard to FIG. 4, an illustration of an alternative illustrativestamped 3D slot dipole antenna 400 is shown. The antenna 400 may havethe same or similar features, such as 3D slot dipoles 304 and 402, butthe height H of the antenna 400 may be higher than the height H of theantenna 300 of FIG. 3. In both of the antennas 300 and 400, the 3D slotdipoles are configured to be in x, y, and z axes. It should beunderstood that configurations and dimensions of the 3D slot dipoleantennas 300 and 400 may be varied depending on frequencies andfrequency bands being received, as understood in the art.

With regard to FIG. 5, an illustration of the stamped 3D slot dipoleantenna 300 of FIG. 3 mounted to the PCB 200 of FIG. 2 is shown. Aspreviously described, the feet 308 may be physically and electricallyconnected to the conductive lines 206 on the PCB 200. In connecting theantenna 300 to the PCB 200, a conductive adhesive (not shown) may beutilized so that an RF signal may be transferred between the antenna 300and conductive lines 206. The feet 308 may be elongated and sized tomatch electrical conductive lines 206 on the PCB 200. By elongating thefeet 308, the antenna 300 may operate as a heat sink for heat producedby the electronic circuit that travels along the electrical conductivelines 206. As shown, the antenna 300 is configured to at least partiallyhouse the electronic device by being affixed to the PCB 200 on which theelectronic device (e.g., ASIC) is also affixed. That is, the antenna 300is positioned on one side of the electronic device and the PCB 200 ispositioned on the other side. It should be understood that in placingthe antenna over the electronic device, antenna height may be selectedto assure physical contact between the antenna and the packaging of theASIC, thereby enabling more efficient transfer of heat from theelectronic device to the antenna, whereby the antenna acts also as aheat sink. It should also be understood that the physical contactbetween the electronic device, such as an ASIC, and the antenna mayinclude a heat conductive adhesive or lubricant to make conducting ofheat from the electronic device to the antenna more effective.

With regard to FIGS. 6A and 6B, illustrations of respective top andbottom isometric views of an alternative illustrative stamped 3D slotdipole antenna 600 are shown. The antenna 600 includes four antennasections 602 a-602 d (collectively 602) inclusive of respective 3D slotdipoles 604 a-604 d (collectively 604). As with the antenna 300 of FIG.3, the antenna 3D slot dipoles 604 provide for receiving RF signals inthree polarizations (i.e., x, y, and z-axis polarizations). As shown inFIG. 6B, the bottom of the antenna 600 defines an opening 606 in which acavity 608 may have an electronic device, such as an ASIC (not shown)that includes rectifiers, in this case four rectifiers or one for eachof the antenna sections 602, to convert the received wireless powersignals received by the respective antenna sections 602. As configured,the antenna 600 may operate as a (i) carrier for housing an electronicdevice and (ii) heat sink for dissipating heat produced by theelectronic device in converting the wireless power signals intoalternative power signals (e.g., DC power signals) for use in chargingor providing operating power for an electronic device (e.g., mobiletelephone). Four feeding points 610 a-610 d used to transition thereceived RF signals onto the PCB are located at the inner portion of therespective 3D slot dipoles 604.

With regard to FIG. 7, a flow diagram of an illustrative process 700 formanufacturing a receiver inclusive of a 3D slot dipole antenna toreceive wireless power signals to charge a battery of or operate anelectronic device is shown. The process 700 may start at step 702, wherea piece of metal may be provided. At step 704, the piece of metal may bestamped to form a 3D slot dipole antenna. The 3D slot dipole antenna mayinclude multiple 3D slot dipoles. In one embodiment, four 3D slotdipoles may be stamped into the metal. The stamping of the metal mayalso form feet at the bottom of the edges of the 3D slot dipole antenna,where the feet may be configured to secure the 3D slot dipole antenna toelectrical conductor lines of a PCB. The 3D slot dipole antenna may beconfigured to provide for receiving dual or circularly polarized RFsignals in multiple polarizations or orientations, such as along the x,y, and z axes. At step 706, the 3D slot dipole antenna may be secured toa PCB inclusive of an electronic circuit configured to convert wirelesspower. The securing of the antenna to the PCB may include securingrespective antenna sections to respective conductive lines that areelectrically connected to the electronic circuit to enable received RFsignals to be converted into power signals for charging or operating anelectronic device inclusive of the antenna. The electronic circuit maybe an electronic circuit inclusive of multiple rectifiers, such as onerectifier for each 3D slot dipole.

The foregoing method descriptions and the process flow diagrams areprovided merely as illustrative examples and are not intended to requireor imply that the steps of the various embodiments must be performed inthe order presented. The steps in the foregoing embodiments may beperformed in any order. Words such as “then,” “next,” etc. are notintended to limit the order of the steps; these words are simply used toguide the reader through the description of the methods. Althoughprocess flow diagrams may describe the operations as a sequentialprocess, many of the operations can be performed in parallel orconcurrently. In addition, the order of the operations may bere-arranged. A process may correspond to a method, a function, aprocedure, a subroutine, a subprogram, etc. When a process correspondsto a function, its termination may correspond to a return of thefunction to the calling function or the main function.

The preceding description of the disclosed embodiments is provided toenable any person skilled in the art to make or use the presentinvention. Various modifications to these embodiments will be readilyapparent to those skilled in the art, and the generic principles definedherein may be applied to other embodiments without departing from thespirit or scope of the invention. Thus, the present invention is notintended to be limited to the embodiments shown herein but is to beaccorded the widest scope consistent with the following claims and theprinciples and novel features disclosed herein.

What is claimed is:
 1. An antenna for receiving electromagnetic waveshaving different polarizations, comprising: a plurality of slots definedby a piece of metal, wherein each of the plurality of slots comprises atleast three continuous segments, wherein, for each of the plurality ofslots: a first segment of the at least three continuous segments is: (i)defined by the piece of metal in a first dimension, and (ii) configuredto receive radio frequency (RF) power transmission waves having a firstpolarization; a second segment of the at least three continuous segmentsis: (i) defined by the piece of metal in a second dimension, distinctfrom the first dimension, and (ii) configured to receive RF powertransmission waves having a second polarization different from the firstpolarization; and a third segment of the at least three continuoussegments is: (i) defined by the piece of metal in a third dimension,distinct from the first and second dimensions, and (ii) configured toreceive RF power transmission waves having a third polarizationdifferent from the first and second polarizations.
 2. The antenna ofclaim 1, wherein: the antenna is connected to an electronic circuit; andthe electronic circuit is configured to convert the RF powertransmission waves received by the antenna into usable power forpowering an electronic device or charging a battery of the electronicdevice.
 3. The antenna of claim 2, wherein: the piece of metal isconfigured to: (i) at least partially house the electronic circuit, and(ii) operate as a heat sink for the electronic circuit.
 4. The antennaof claim 2, wherein: the electronic circuit is mounted on a circuitboard having a plurality of conductive traces; the electronic circuit iscoupled with respective first ends of the plurality of conductivetraces; and feet of the piece of metal are coupled with respectivesecond ends of the plurality of conductive traces, thereby coupling theantenna with the electronic circuit.
 5. The antenna of claim 4, wherein:the respective second ends of the plurality of conductive traces areformed along a perimeter of the circuit board; and the feet of the pieceof metal substantially cover the perimeter.
 6. The antenna of claim 1,wherein two continuous segments of the at least three continuoussegments included in each of the plurality of slots are substantiallyorthogonally positioned relative to each other.
 7. The antenna of claim1, wherein the first dimension is orthogonal to the second dimension. 8.The antenna of claim 1, wherein: a first slot of the plurality of slotsis oriented along a first axis; a second slot of the plurality of slotsis oriented along a second axis; and the first axis is substantiallyorthogonal to the second axis.
 9. The antenna of claim 8, wherein: thefirst slot has a shape; the second slot also has the shape; and thefirst and second slots are distinct and separate from each other. 10.The antenna of claim 9, wherein: a third slot of the plurality of slotsis oriented along the first axis; the third slot also has the shape; thefirst slot is oriented in a first direction along the first axis; thethird slot is oriented in a second direction along the first axis, thesecond direction being opposite to the first direction; and the thirdslot is distinct and separate from the first and second slots.
 11. Theantenna of claim 1, wherein: the first segment of the at least threecontinuous segments in each of the plurality of slots is defined by asurface of the piece of metal; feet of the piece of metal are offsetfrom the surface of the piece of metal; sidewalls of the piece of metalextend from the feet to the surface; and the second segment of the atleast three continuous segments in each of the plurality of slots isdefined by one of the sidewalls of the piece of metal.
 12. The antennaof claim 11, wherein: the surface of the piece of metal is in the firstdimension; and the sidewalls of the piece of metal are in the seconddimension.
 13. The antenna of claim 11, wherein the antenna operates asa heat sink by dissipating heat via the feet of the piece of metal. 14.The antenna of claim 11, wherein the second segment of the at leastthree continuous segments in each of the plurality of slots is furtherdefined by the feet of the piece of metal.
 15. The antenna of claim 1,wherein the RF power transmission waves are transmitted by a remotetransmitter.
 16. The antenna of claim 1, wherein the piece of metaloperates as a heat sink for the electronic circuit while the RF powertransmission waves are being received by the antenna.
 17. The antenna ofclaim 1, wherein: the RF power transmission waves having the firstpolarization are horizontally polarized RF power transmission waves; andthe RF power transmission waves having the second polarization arevertically polarized RF power transmission waves.
 18. The antenna ofclaim 1, wherein, for each of the plurality of slots: the first segmentis defined substantially along the x-axis; the second segment is definedsubstantially along the y-axis; and the third segment is definedsubstantially along the z-axis.
 19. A method of manufacturing anantenna, the method comprising: stamping a piece of metal, wherein: thestamped piece of metal defines a plurality of slots; and each of theplurality of slots comprises at least three continuous segments, where:a first segment of the at least three continuous segments is: (i)defined by the piece of metal in a first dimension, and (ii) configuredto receive radio frequency (RF) power transmission waves having a firstpolarization; a second segment of the at least three continuous segmentsis: (i) defined by the piece of metal in a second dimension, distinctfrom the first dimension, and (ii) configured to receive RF powertransmission waves having a second polarization different from the firstpolarization; and a third segment of the at least three continuoussegments is: (i) defined by the piece of metal in a third dimension,distinct from the first and second dimensions, and (ii) configured toreceive RF power transmission waves having a third polarizationdifferent from the first and second polarizations.
 20. A receiver forreception of wireless power transmission, the receiver comprising: anantenna for receiving electromagnetic waves having differentpolarizations, including: a plurality of slots defined by a piece ofmetal, wherein each of the plurality of slots comprises at least threecontinuous segments, wherein, for each of the plurality of slots: afirst segment of the at least three continuous segments is: (i) definedby the piece of metal in a first dimension, and (ii) configured toreceive radio frequency (RF) power transmission waves having a firstpolarization; a second segment of the at least three continuous segmentsis: (i) defined by the piece of metal in a second dimension, distinctfrom the first dimension, and (ii) configured to receive RF powertransmission waves having a second polarization different from the firstpolarization; and a third segment of the at least three continuoussegments is: (i) defined by the piece of metal in a third dimension,distinct from the first and second dimensions, and (ii) configured toreceive RF power transmission waves.